One type of cutting tool is a power saw that includes an electrical motor mounted below a work surface. Users frequently refer to this type of power saw as a table saw, because the work surface resembles a tabletop. The table has an opening that allows a portion of the cutting tool, such as a saw blade, to extend above the work surface of the table. The blade, which is rotatably connected to the electrical motor, is movable relative to the surface of the table to enable a user of the table to make cuts of a particular depth or angle. For example, to adjust the height of the blade, a user may position a workpiece adjacent to the blade and then adjust the height of the blade such that the apex of the blade extends just above the thickest portion of the workpiece. To cut the workpiece, a user positions the workpiece on the table, such that a line representing the cutting path of the blade is aligned with a region of the workpiece to be cut, energizes the motor to rotate the blade, and moves the workpiece toward the rotating blade. As the blade cuts through the workpiece, it generates dust, chips, and other workpiece debris, which may be collected by a debris collection system.
Table saw debris collection systems, commonly referred to as dust collectors, direct the workpiece debris into a collection receptacle such as a bag or other suitable container. Additionally or alternatively, an external negative pressure source, such as a vacuum may be configured to draw the debris from a debris exit port of the table saw into a container. Some users, however, may desire a table saw having a dust collector, which functions effectively without a separate negative pressure source.
The efficiency of most dust collectors or dust extractors is relatively low in the absence of a vacuum applied to the discharge outlet. For a typical table saw that does not utilize vacuum, sometimes less than 50% of the dust/debris is captured in the collection bag. Even with a vacuum source, collection efficiency is typically around 90%. It is apparent that any dust that is not collected either falls around the work area or clogs the power tool, requiring user intervention to clear the working area. It is desirable to provide a dust collection or extraction system that extracts as close to 100% of the dust as possible. It is also desirable to provide such a system that can work well in the absence of a vacuum source.